Perceptions of attitudes toward statistics among medical undergraduates: insights from a regional medical college in China.

BACKGROUND: Among Chinese medical students, medical statistics is often perceived as a formidable subject. While existing research has explored the attitudes of Chinese postgraduate medical students towards statistics and its impact on academic performance, there is a scarcity of studies examining the attitudes of Chinese medical undergraduates on this subject. This study endeavors to scrutinize the attitudes of Chinese medical undergraduates towards statistics, assessing their ramifications on learning achievements, and delving into the influence of demographic factors. METHODS: 1266 medical undergraduates participated in this study, completing a questionnaire that included SATS-36 and additional queries. Furthermore, an examination was administered at the end of the medical statistics course. The analysis encompassed the SATS score and exam scores, examining both the overall participant population and specific demographic subgroups. RESULTS: Undergraduate medical students generally exhibit a favorable disposition towards statistics concerning Affect, Cognitive Competence, and Value components, yet harbor less favorable sentiments regarding the Difficulty component of SATS-36, aligning with previous research findings. In comparison to their postgraduate counterparts, undergraduates display heightened enthusiasm for medical statistics. However, they demonstrate a lower cognitive capacity in statistics and tend to underestimate both the value and difficulty of learning statistics. Despite these disparities, undergraduate medical students express a genuine interest in statistics and exhibit a strong dedication to mastering the subject. It is noteworthy that students' attitudes toward statistics may be influenced by their major and gender. Additionally, there exists a statistically significant positive correlation between learning achievement and the Affect, Cognitive Competence, Value, Interest, and Effort components of the SATS-36, while a negative correlation is observed with the Difficulty component. CONCLUSION: Educators should carefully consider the influence of attitudes toward statistics, especially the variations observed among majors and genders when formulating strategies and curricula to enhance medical statistics education.

Association between visceral fat area and serum uric acid in Chinese adults: A cross-sectional study.

BACKGROUND AND AIMS: Hyperuricemia has become a vital public health problem affecting the health of residents. The visceral fat area (VFA) is closely related to many chronic diseases. However, the association between VFA and hyperuricemia within the Chinese adult population remains nebulous. The aim of the research is to assess the relationship between VFA and serum uric acid levels. METHODS AND RESULTS: From June 2020 to June 2021, a total of 340 Chinese adults (240 in the control group and 100 in the hyperuricemia group) were recruited from the physical examination center of Hongqi Hospital Affiliated to Mudanjiang Medical University. General demographic characteristics were collected by questionnaire. VFA was measured by a body composition analyzer, and serum biochemical indices were detected by clinical laboratory. VFA in the hyperuricemia group was higher than in the control group (P＜0.05). Further, VFA demonstrated a positive correlation with serum uric acid level (rs = 0.370, P＜0.001). To further explore this relationship, we divided the VFA into quartiles (＜P25, P25-P50, P50-P75, ≥P75). Upon comparison with the ＜P25 group, we found the VFA in the P25-P50, P50-P75, and ≥P75 groups to be associated with a substantially escalated risk of hyperuricemia, even after adjusting for age, gender, body weight, fasting plasma glucose, calcium, alanine transaminase, urea, alkaline phosphatase, and γ-glutamyltransferase. The OR and 95% CI were 2.547 (1.023, 6.341), 3.788 (1.409, 10.187) and 3.723 (1.308, 10.595), respectively (P＜0.05). CONCLUSION: VFA has a positive correlation with serum uric acid levels and may serve as a crucial predictive marker for hyperuricemia.

NMR spectroscopy based metabolomics confirms the aggravation of metabolic disorder in metabolic syndrome combined with hyperuricemia.

BACKGROUND AND AIMS: Hyperuricemia (HUA) were associated with Metabolic syndrome (MetS) and its components. However, the molecular mechanism of uric acid in the development of MetS was not well elucidated. The aim of this study was developing a systemic metabolic profile by using metabolomics approach to explore the molecular mechanism of uric acid in the development of MetS. METHODS AND RESULTS: Anthropometric, clinical biochemical data, and serum samples were collected from patients with MetS, MetS combined with HUA (MetS & HUA) and healthy controls. 1H nuclear magnetic resonance (NMR) spectroscopy was used to detect endogenous small molecule metabolites of serum samples, then multivariate statistical analysis was applied to distinguish samples of different groups. In addition, pathway analysis was performed to contribute to understanding the metabolic change. By serum metabolic profiling, a total of 20 identified metabolites including lipids, amino acids, and organic acids were significantly altered in MetS and MetS & HUA patients. MetS & HUA patients presented a more severe disorder in both identified metabolites and BMI and biochemical indexes. According to pathway analysis, there were 3 and 5 metabolic pathways remarkably perturbed in MetS and MetS & HUA group respectively. CONCLUSION: Taken together, we identified disordered metabolites and related pathways for both MetS and MetS & HUA patients, and found a more severe metabolic disorder in MetS patients who has a higher serum uric acid. Our study provides biochemical insights into the metabolic alteration for the progress of MetS.

One-step electrodeposition preparation of polyaniline/f-MWCNTs as electrochemical sensors for detection of 10-hydroxycamptothecine.

In our work, one-step electro-deposition method was adopted to produce polyaniline (PANI) and functional multiwalled carbon nanotubes (f-MWCNTs) films on glass carbon electrodes, and the modified electrodes were applied as an electrochemical sensor for determination of 10-hydroxycamptothecine (10-HCPT). The f-MWCNTs were handled by ultrasound processing in concentrated oxidizing acid solution, which can obtain a wonderful dissolution in water and attach new functional groups, such as -COOH and -OH. Then, aniline monomer could polymerize on the surface easily. The surface characterization was investigated using various techniques including scanning electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, and electro-catalytic properties were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Under optimal conditions, the resulting of PANI/f-MWCNTs sensor showed a wide linear range (3 × 10-9 to 7 × 10-7 mol L-1 ) and a low detection limit (1 × 10-9 mol L-1 ), which is attributing to its large special surface area and good conductivity. Moreover, the modified electrodes are convenient to fabricate, which can be used to detect 10-HCPT in urine samples successfully.

A sandwich-configuration electrochemiluminescence immunoassay based on Cu2O@OMC-Ru nanocrystals and OMC-MoS2 nanocomposites for determination of alpha-fetoprotein.

A sandwich-format electrochemiluminescence (ECL) immunosensor has been developed for alpha-fetoprotein (AFP) detection based on the use of ordered mesoporous carbon-molybdenum disulfide (OMC-MoS2) as a sensor platform and cuprous oxide @ ordered mesoporous carbon-Ru(bpy)32+ (Cu2O@OMC-Ru) composites as signal tags. OMC alongside MoS2 plays a synergistic role in improving the electrochemical performance of the electrode in the electron transfer process. The uniform cubic-shaped Cu2O@OMC-Ru nanocrystals display excellent luminous efficiency, with a signal amplification strategy of OMC-MoS2 synergistic enhancement and Cu2O@OMC which is capable of immobilizing more Ru(bpy)32+ serving as a tracing tag to label antibodies. A detectable ECL emission at a Cu2O@OMC-Ru nanocrystals modified electrode is initiated at an applied voltage of +1.15 V (scanning range: 0-1.2 V), in the presence of the tripropylamine (TPA) as coreactant. With the increase in AFP concentration, the loading of Cu2O@OMC-Ru at the electrode increases. Afterward, the ECL detection of AFP shows a wide linear range from 0.1 pg/mL to 10 ng/mL with a correlation coefficient of 0.9964 and a detection limit of 0.011 pg/mL (S/N = 3) under the optimal experimental conditions. The recoveries were in the range 91.2-97.1% with RSD varying from 4.8 to 8.5%. Overall, the novel immunosensor has been successfully applied to the analysis of human serum samples, indicating a great potential for application in clinical diagnostics.

Aberrant Methylation of Suppressor of Cytokine Signaling 1 (SOCS1) Gene as a Biomarker for Early Prediction and Diagnosis of Bladder Cancer.

BACKGROUND: SOCS1 protein, the negative regulatory protein of the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling pathway, may inhibit signaling of JAK-STAT pathway by several cytokines and has tumor suppressor activity. Methylation of CpG island in the promoter region of SOCS1 gene has often been shown to inactivate the SOCS1 gene in certain human cancers. However, the precise role of SOCS1 in bladder cancer is unclear. METHODS: Two hundred forty-seven patients with BCa and 243 healthy controls were enrolled from Tumour Hospital Affiliated to Harbin Medical University, Hongqi Hospital Affiliated to Mudanjiang Medical University, and Mudanjiang Tumour Hospital from September 2013 to March 2019. The methylation rate in the promoter region of the SOCS1 among all participants were detected using the MassARRAY EpiTYPER system. A ROC curve was set out to analyze SOCS1 gene promoter CpG island methylation for BCa diagnosis. RESULTS: There was a significantly higher methylation rate in BCa compared to controls. Then we assessed the methylation rate of different CpG islands in SOCS1 gene among BCa cases and normal controls. Methylation rate was shown to vary among different CpG islands. The methylation rates of CpG islands were shown to vary among different grades. We observed that the methylation rate of different CpG islands vary according to pathological grades. CONCLUSIONS: Our study demonstrates that aberrant methylation of CpG island in the promoter region of SOCS1 gene may be involved in occurrence, progression, and prognosis of BCa and, thus, may serve as an independent diagnosis and prognostic biomarker.

Electrochemical immunoassay for the carcinoembryonic antigen based on Au NPs modified zeolitic imidazolate framework and ordered mesoporous carbon.

An electrochemical immunoassay for the carcinoembryonic antigen is described. It is based on the use of Au NPs modified zeolitic imidazolate framework (ZIF-8) and ordered mesoporous carbon (OMC). Au NPs@ZIF-8 was synthesized by reduction of chloroauric acid. It serves as immobilization support nanocarrier to increase antibody loading due to its large surface area. OMC was dropped on a glassy carbon electrode to improve electrochemical signals due to enhanced electrical conductivity. Differential pulse voltammetry was carried out to record electrochemical responses (best measured at 0.26 V vs. Ag/AgCl). The immunosensor demonstrated excellent electrochemical performance with a linear determination range of 5 pg mL-1 to 400 ng mL-1 and a determination limit of 1.3 pg mL-1 (S/N = 3). The sensor also exhibited high selectivity, good stability, and acceptable reproducibility. Graphical abstract Scheme 1 Schematic representation of fabrication of the immunosensor for CEA determination.

Long-chain unsaturated fatty acids as possible important metabolites for primary angle-closure glaucoma based on targeted metabolomic analysis.

Primary angle-closure glaucoma (PACG) is a severe chronic neurodegenerative disease in Asia. Identification of important metabolites associated with PACG is crucial for early intervention and advancing knowledge of the disease mechanism. We applied gas chromatography-mass spectrometry (GC-MS) for targeted metabolomic analysis on serum samples from 38 newly diagnosed PACG patients and 48 controls. Palmitoleic acid (PA), linoleic acid (LA), γ-linolenic acid (GLA) and arachidonic acid (ARA) were identified as important metabolites associated with PACG. PA and GLA were significantly elevated (p < 0.05), while LA and ARA showed a significantly decreased trend (p < 0.05) in PACG group compared with the control group. Also, significant negative correlations were observed between LA and ARA levels and intraocular pressure of the left eye (rs = -0.750, p < 0.001; rs = -0.729, p < 0.001) and the right eye (rs = -0.786, p < 0.001; rs = -0.764, p < 0.001). Serum GLA level was positively correlated with intraocular pressure of the left eye (rs = 0.233, p = 0.031) and the right eye (rs = 0.226, p = 0.036). Our findings revealed a significant difference of the serum free fatty acid metabolic profiles between PACG patients and control subjects. Furthermore, PA, LA, ARA and GLA appear to have clinical applications for the screening of PACG.

Electrochemical Determination of Uric Acid at CdTe Quantum Dot Modified Glassy Carbon Electrodes.

Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of uric acid (UA) at a CdTe quantum dot (QD) modified the glassy carbon electrode (GCE). CdTe QDs, as new semiconductor nanocrystals, can greatly improve the peak current of UA. The anodic peak current of UA was linear with its concentration between 1.0×10(-6) and 4.0×10(-4) M in 0.1 M pH 5.0 phosphate buffer solution. The LOD for UA at the CdTe electrode (1.0×10(-7) M) was superior to that of the GCE. In addition, we also determined the effects of scan rate, pH, and interferences of UA for the voltammetric behavior and detection. The results indicated that modified electrode possessed excellent reproducibility and stability. Finally, a new and efficient electrochemical sensor for detecting UA was developed.

Serum free fatty acids level in senile cataract.

PURPOSE: To evaluate and compare the levels of free fatty acids between senile cataract patients and normal controls. METHODS: Fifty consecutive patients with newly diagnosed senile cataract and 50 age- and gender-matched controls were evaluated. Subjects/patients were randomized according to selection criteria. The levels of free fatty acids (FFAs) in serum were measured by gas chromatography-mass spectrometry (GC-MS). Sixteen fatty acids from 14:0 to 24:1 were identified. The values were compared between cataract and control groups by parametric independent sample test and Mann-Whitney U tests. RESULTS: A significant decrease was observed in arachidonic acid (C20:4n-6, ARA), cis-4,7,10,13,16,19-docosahexaenoic acid (C22:6n-3, DHA), tetracosanoic acid (C24: 0), cis-7,10,13,16,19-docosapentaenoic acid (C22:5n-6, DPA), total n-3 long-chain polyunsaturated fatty acids (LC-PUFAs), total n-6 LC-PUFAs, total fatty acids, unsaturated fatty acids (USFAs), polyunsaturated fatty acids (PUFAs), and nonessential fatty acid levels in patients with senile cataract in comparison with healthy persons (p < 0.05). CONCLUSIONS: The levels of FFA including DPA, tetracosanoic acid, ARA, and DHA were significantly lower in the senile cataract group compared to that in the normal controls. FFA may be helpful in preventing senile cataract.

LncRNA XIST promotes bladder cancer progression by modulating miR-129-5p/TNFSF10 axis.

BACKGROUND: The differential expression, biological function, and ceRNA regulatory mechanism of lncRNA XIST in bladder cancer (BC) were investigated, and its clinical values for the early diagnosis of bladder cancer patients were elucidated. METHODS: qRT-PCR was employed to detect the expression patterns of lncRNA XIST, miR-129-5p and TNFSF10. The biological functions were measured by CCK8 assay, wound healing assay and transwell assay. Bioinformatics analysis and Dual-Luciferase reporter assay were employed to evaluate the interactions between the lncRNA XIST, miR-129-5p and TNFSF10. RESULTS: LncRNA XIST and TNFSF10 were highly expressed and miR-129-5p was low expressed (P < 0.05) in bladder cancer cell line. The depletion of lncRNA XIST inhibited BC proliferation, migration and invasion. Mechanistically, lncRNA XIST could sponge miR-129-5p to regulate TNFSF10 expression in bladder cancer. Furthermore, compared with adjacent tissues, lncRNA XIST and miR-129-5p were lowly expressed (P < 0.01) in bladder cancer tissues, and TNFSF10 was highly expressed (P < 0.001). miR-129-5p and TNFSF10 were associated with the risk of bladder cancer (P < 0.05); the difference in AUC values for the diagnosis of bladder cancer by lncRNA XIST (AUC = 0.739), miR-129-5p (AUC = 0.850) and TNFSF10 (AUC = 0.753) was statistically significant (P < 0.01), and the three genes combined AUC was 0.900, 95%CI was 0.842-0.958 with a sensitivity of 83.3% and specificity of 86.7%. CONCLUSION: XIST, an elevated lncRNA in bladder cancer, inhibition of which could suppress the progression of BC. LncRNA XIST and miR-129-5p could form ceRNA to regulate the expression of TNFSF10.

An electrochemical ratiometric immunosensor for the detection of NMP22 based on ZIF-8@MWCNTs@Chit@Fc@AuNPs and AuPt-MB.

Nuclear matrix protein 22 (NMP22) is one of the most important tumor markers of bladder cancer and is significantly elevated in the urine of bladder cancer patients. Therefore, in this work, a highly sensitive ratiometric electrochemical immunosensor was constructed to detect NMP22 based on ZIF-8@MWCNTs@Chit@Fc@AuNPs composites. ZIF-8 had a large surface area and good adsorption ability. Multi-Walled Carbon Nanotubes (MWCNTs) can optimize the electrical conductivity of ZIF-8, so that the electrode surface of ferrocene (Fc) obtains a stable and strong electrochemical signal. In addition, AuPt-MB provided another strong detection signal methylene blue (MB) while immobilizing the secondary antibody (Ab2) through Au-N and Pt-N bonds. A ratiometric electrochemical sensor was formed based on ZIF-8@MWCNTs@Chit@Fc@AuNPs and AuPt-MB, which showed a great linear connection between IMB/IFc and the logarithmic concentration of NMP22 with a detection limit of 3.33 fg mL-1 (S/N = 3) under optimized specifications in the concentration interval of 0.01 pg mL-1 to 1000 ng mL-1. In addition, the ratiometric immunosensor showed good selectivity and stability.

Survivin as a potential biomarker in the diagnosis of bladder cancer: A systematic review and meta-analysis.

Early detection, diagnosis, and treatment take on critical significance in preventing and treating bladder cancer. As indicated by numerous studies, survivin can serve as a biomarker of bladder cancer, whereas the results of a wide variety of studies have been controversial. This paper is to assess the accuracy of survivin in the diagnosis of bladder cancer by a meta-analysis. The studies regarding the diagnosis of bladder cancer using survivin were systematically retrieved from the CNKI, WanFang, CBM, VIP, Web of science, cochrane library and pubmed were extracted, and the literature quality was assessed. Meta-analysis was conducted using STATA 16.0 MP. 2,082 relevant studies were searched, and 40 studies were finally covered for meta-analysis. The pooled specificity and pooled sensitivity of survivin mRNA was 0.95 (95%CI: 0.91, 0.97) and 0.94 (95%CI: 0.88, 0.97). The pooled specificity and pooled sensitivity of survivin protein reached 0.95 (95%CI: 0.90, 0.97) and 0.87 (95%CI: 0.78, 0.92). The pooled positive likelihood ratio, pooled negative likelihood ratio, the area under the curve, and diagnostic odds ratio for survivin mRNA reached 17.7 (95%CI: 10.3, 30.6), 0.07 (95%CI: 0.04, 0.12), 0.98 (95%CI: 0.97, 0.99) and 266 (95%CI: 114, 621), respectively. For survivin protein was 16.4 (95%CI: 7.9, 33.9), 0.14 (95%CI: 0.08, 0.24), 0.97 (95%CI: 0.95, 0.98) and 117 (95%CI: 38, 357), respectively. Survivin takes on great significance in diagnosing bladder cancer. However, due to some limitations in the number and quality of covered studies, this conclusion should be validated through additional higher quality clinical studies.

Noncoding RNAs as a potential biomarker for the prognosis of bladder cancer: a systematic review and meta-analysis.

OBJECTIVE: The relationship between noncoding RNAs and the prognosis of bladder cancer (BC) is still controversial. The purpose of this study is to evaluate the relationship between noncoding RNAs and prognosis by meta-analysis. METHODS: Comprehensive retrieval of PubMed, Embase, the Cochrane Library, the Web of Science, CNKI, and WanFang databases is related to the correlation between noncoding RNAs and the prognosis of BC. Data were extracted, and the literature quality was evaluated. STATA16.0 served for the meta-analysis. RESULTS: 1. CircRNAs: High circ-ZFR expression led to poor overall survival (OS) of BC. 2. LncRNAs: Low lnc-GAS5 expression predicted poor OS of BC, high lnc-TUG1 expression predicted poor OS of BC. 3. MiRNAs: High miR-21 expression predicted poor OS of BC, high miR-222 expression led to poor OS of BC, high miR-155 expression predicted poor progression-free survival (PFS) of BC, high miR-143 expression caused poor PFS of BC, low miR-214 expression could result in poor recurrence-free survival (RFS) of BC. CONCLUSIONS: High circ-ZFR, lnc-TUG1, miR-222, and miR-21 expressions were correlated with poor OS of BC; high miR-155 and miR-143 expression predicted poor PFS of BC; low lnc-GAS5 expression predicted poor OS of BC; low miR-214 expression predicted poor RFS of BC.

Determination of purines in prepackaged food using optimum acid hydrolysis followed by high performance liquid chromatography.

A high performance liquid chromatography was established to determine purine content of prepackaged food. Chromatographic separation was performed on Agilent5 TC-C18 column. Ammonium formate (10 mmol/L, pH = 3.385) and methanol (99:1) were used as mobile phase. Purine concentration and peak area showed good linear relationships in the range from 1 to 40 mg/L (guanine, hypoxanthine, adenine) and xanthine exhibited a good linear relationship ranged from 0.1 to 4.0 mg/L. Recoveries of four purines ranged from 93.03% to 107.42%. Purine content in prepackaged food was following: animal derived prepackaged food: 16.13-90.18 mg/100 g; beans and bean products: 66.36-157.11 mg/100 g; fruits and fruit products: 5.64-21.79 mg/100 g; instant rice and flour products: 5.68-30.83 mg/100 g; fungi, algae, fungi and algae products: 32.57-70.59 mg/100 g. This proposed method had good precision and accuracy with a wide linear range for detection of purine. Animal derived prepackaged food was purine-rich food, purine content of plant derived prepackaged food varied greatly.

[Purine in common plant food in China].

OBJECTIVE: To determine the content of purine in plant food in China with HPLC. METHOD: HPLC analysis was applied on Waters Atlantis T3 column (4.6mm x 250mm x 5 microm), using 10.0 mmol/L NH4COOH (pH 3.6) and CH3OH (99%/1%) as mobile phase and running at a flow rate of 1.0 ml/min. The column temperature was 30 degrees C, and the detection wavelength was at 254nm. RESULTS: The content of purine varied significantly in different kinds of plant food. The content of purine in dried fungi and dried legumes and legume products was higher than that in other food, the content of purine in vegetables and vegetable products and fruits and fruit products was low. As a whole, the content of purine was: dried fungi and algae > dried legumes and legume products > nuts and fresh > seeds fungi and algae > cereal and cereals products > vegetables and vegetable products > fruit and fruit products > tubers, starches and products. CONCLUSION: The content of purine of dried fungi and algae and dried legumes and legume products in plant food was high. The content of purine was varied significantly in different kinds of plant food.

A risk score for the prognosis prediction of the muscle-invasive bladder cancer patients who received gemcitabine plus cisplatin chemotherapy.

To develop an individualized gene-based risk score to predict the prognosis of muscle-invasive bladder cancer (MIBC) patients who received GC regimens. We downloaded transcriptome profiling data and clinical information from the Cancer Genome Atlas (TCGA) database. We identified 1854 survival-associated genes and then constructed the risk score based on six special genes selected from the survival-associated genes. We divided patients into high-risk and low-risk groups according to the median risk score. High-risk patients have significantly poorer overall survival than low-risk patients (log-rank test chi-square = 38.08, p = 7e-10, C-index = 0.785, se = 0.032). The risk score was evaluated by Kaplan-Meier survival curve, time-dependent ROC curves, and C-index. Multivariate Cox regression and nomogram suggested that the risk score was an independent prognostic indicator. Gene set enrichment analysis indicated that the survival-associated genes were significantly enriched in immune-related terms. Among six special genes, CHPF2, TRAV26-2, and BTF3P12 were found to be immune-related genes. In conclusion, our risk score provided an indicator to predict the prognosis of MIBC patients who received GC regimens and potential immunotherapeutic targets for MIBC.

A label-free electrochemical immunosensor for CA125 detection based on CMK-3(Au/Fc@MgAl-LDH)n multilayer nanocomposites modification.

A label-free electrochemical immunosensor was constructed for cancer antigen 125 (CA125) detection based on multiple-enlargement means of layer-by-layer (LBL) assembly of ordered mesoporous carbon (CMK-3), gold nanoparticles (Au NPs) and MgAl layered double hydroxides containing ferrocenecarboxylic acid (Fc@MgAl-LDH). A CMK-3(Au/Fc@MgAl-LDH)n multilaminate nanocomposites was designed using technology of LBL self-assembly among negatively charged Au NPs, positively charged CMK-3 and Fc@MgAl-LDH nanosheets. The CMK-3(Au/Fc@MgAl-LDH)n multilaminate nanocomposites was used as carriers to increase the immobilization of antibody and the number of loading Fc, conductors to strengthen conductivity and enhancers to amplify signal of Fc step-by-step. Besides, this special and excellent way of LBL assembly can immensely amplify the signal of immunosensor and more immobilize the biomolecules, and label-free method is a more simple the measuring way and the procedure. The immunosensor displayed a wider linear range of 0.01 U ml-1-1000 U ml-1 and a lower detection limit of 0.004 U ml-1. Therefore, the sensor can stablely and accurately be applied for CA125 detection in clinical cancer diagnosis.

Electrochemical Detection of Nuciferine in the Lotus Leaf Based on Efficient Catalysis by Zirconium-MOFs.

BACKGROUND: Nuciferine is an amorphine alkaloid in lotus leaf that has anti-inflammatory, lipid-lowering and hypoglycemic effects, so the quantitation of detected nuciferine is important. OBJECTIVE: An electrochemical method was developed for nuciferine detection based on efficient catalysis by Zr-MOFs (Metal-organic frameworks). METHODS: In this work, the ratiometric electrochemical method was developed for nuciferine detection based on efficient catalysis by Zr-MOFs. UiO66 is a Zr-MOFs nanomaterial and can absorb methylene blue (MB) by electrostatic action to form UiO66-MB nanocomposite. The UiO66-MB nanocomposite can be used as an enhancer to catalyze nuciferine decomposition and a carrier to provide a two-dimensional environment for the reaction of nuciferine. Moreover, good catalytic properties of UiO66 were first time used for the detection of nuciferine. RESULTS: This method has a linear detection range from 0.1 to approximately 20 µg/mL, and a low detection limit of 0.03 µg/mL (S/N=3). The recovery was from 98.1 to 102% and the RSD was from 0.45 to 3.65%, indicating that the proposed method can be applied for the analysis of real samples. CONCLUSION: The proposed electrochemical method can be used to detect nuciferine in lotus leaves. HIGHLIGHTS: The ratiometric electrochemical method was used for the detection of nuciferine. The MB can be used as an internal standard for anti-interference. And, UiO66 is used to catalyze the decomposition of nuciferine. Great catalytic properties of UiO66 were first time used for the detection of nuciferine.

Sandwich-type immunosensor based on COF-LZU1 as the substrate platform and graphene framework supported nanosilver as probe for CA125 detection.

CA125 is a tumor marker which mainly exists in ovarian, the detection for it with high sensitivity is conducive to improve the effectiveness of tumor prevention and control at early state. Multi-layer graphene oxide derivatives from graphene, and has poor conductivity and high stacked properties that limit its further application. Multi-layer reduced graphene oxide frame (MrGOF) was composed of single-layer graphene sheet and exhibited 3D structure with good dispersion, better conductivity and electrochemical properties after multi-layer graphene oxide underwent alkaline peeling and thermally reduction, the modified graphene are easy to load and combine functional groups and metal nanoparticles. Covalent organic frameworks (COFs) presents a stable frame and through covalent bond connection and has porous properties to adsorb biomolecules, which allows the immobilization of antibody molecules by the porosity and improve the sensitivity of the detection in sensing field. Through the adsorption of COFs for antibody and the probe labeled with functional graphene, we constructed a sandwich type immunosensor with the new material COF-LZU1 as the platform to anchor the CA125 first-antibody and MrGOF combined with amino group and loaded with silver nanoparticles (AgNPs) as the probe to detect tumor marker CA125. The linear range of detection was from 0.001 U/mL to 40 U/mL, with the detection limit was calculated to be 0.00023 U/mL (S/N =3). The prepared immunosensor showed a good application ability for real human serum, which can be attributed to the adsorption of COF-LZU1 for the CA125 first-antibody, and ability to deliver electrons and signal amplification of AgNPs anchored on the sheet structure of MrGOF.